Immunoreactive antigens in a subfraction of a KCL extract of heart tissue from mice inoculated with Coxsackievirus B3 (CVB3) will be studied for their possible role in CVB3-induction of myocarditis in adolescent CD-1 mice, using as sources of heart tissues, mice inoculated with several myocarditic and amyocarditic variants of CVB3. The latter virus variants are revertants of temperature-sensitive (ts) mutants of CVB3 which belong to one of three different complementation groups. Two-dimensional polyacrylamide gel electrophoresis will be used to separate 125 I-labeled proteins in the subfraction of immunoreactive autigens from the various heart sources in an attempt to detect differences in the protein profiles of subfractions from heart tissues of mice inoculated with myocarditic and amyocarditic variants. Murine Endothelial cells in primary cultures replicate CVB3 whereas myocytes do not. We will determine whether the former cells can be established as carrier cultures and perhaps serve as the focus for in vivo myocardial lesion formation. Neonatal mice inoculated with a ts1 variant are resistant as adolescents to CVB3-induction of myocarditis. We will determine whether the resistance can in part be attributed to T suppressor cells in the lymphoid population.